Synthesis of a KIT-6 mesoporous sulfonic acid catalyst to produce biodiesel from cashew nut oil

• Published in: Brazilian journal of chemical engineering Vol. 39; no. 4; pp. 1001 - 1011
• Main Authors: Uchoa, Antonia F. J., do Valle, Camila P., Moreira, Denise R., Bañobre-López, Manuel, Gallo, Juan, Dias, Francisco S., Anderson, Michael W., Ricardo, Nágila M. P. S.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.12.2022
• Subjects: Chemistry; Chemistry and Materials Science; Industrial Chemistry/Chemical Engineering; Original Paper; Cashew nut oil; Butanol; Transesterification; KIT-6; Biodiesel
• ISSN: 0104-6632; 1678-4383
• DOI: 10.1007/s43153-021-00216-0

In this work, KIT-6 silica functionalized with sulfonic acid by the co-condensation method was prepared and evaluated as a catalyst in the transesterification of Brazilian cashew nut oil (BCNO) with butanol for biodiesel synthesis. The catalyst was characterized by SAXS, TEM, N 2 adsorption–desorption measurements, 29 Si MAS NMR and 13 C CP-MAS NMR to prove the structural integrity of the incorporated organic group and to show the ordered structure, morphology and porosity, respectively. Small-angle XRD confirmed the formation of the mesophase of the synthesized materials. TEM images demonstrated the well-ordered arrangement of the pores and their uniformity throughout the grains, in addition to the highly ordered nature of the cubic mesostructures. The KIT-6 propylsulfonic acid catalyst was able to produce a 70% butyl ester yield, as determined by 1 H NMR spectroscopy in 6 h reaction with a BuOH/BCNO molar ratio of 30:1, 140 °C and a 6 wt% of catalyst mass relative to starting oil mass in the reaction. The KIT-6-S catalyst can be reused for two cycles without loss of catalytic activity.